4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: Zijun Hu quic_zijuhu@quicinc.com
[ Upstream commit c0fd973c108cdc22a384854bc4b3e288a9717bb2 ]
Return -EIO instead of 0 for below erroneous bus attribute operations: - read a bus attribute without show(). - write a bus attribute without store().
Signed-off-by: Zijun Hu quic_zijuhu@quicinc.com Link: https://lore.kernel.org/r/20240724-bus_fix-v2-1-5adbafc698fb@quicinc.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/base/bus.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/base/bus.c b/drivers/base/bus.c index e06a57936cc96..aad13af4175b8 100644 --- a/drivers/base/bus.c +++ b/drivers/base/bus.c @@ -103,7 +103,8 @@ static ssize_t bus_attr_show(struct kobject *kobj, struct attribute *attr, { struct bus_attribute *bus_attr = to_bus_attr(attr); struct subsys_private *subsys_priv = to_subsys_private(kobj); - ssize_t ret = 0; + /* return -EIO for reading a bus attribute without show() */ + ssize_t ret = -EIO;
if (bus_attr->show) ret = bus_attr->show(subsys_priv->bus, buf); @@ -115,7 +116,8 @@ static ssize_t bus_attr_store(struct kobject *kobj, struct attribute *attr, { struct bus_attribute *bus_attr = to_bus_attr(attr); struct subsys_private *subsys_priv = to_subsys_private(kobj); - ssize_t ret = 0; + /* return -EIO for writing a bus attribute without store() */ + ssize_t ret = -EIO;
if (bus_attr->store) ret = bus_attr->store(subsys_priv->bus, buf, count);